Heat insulating tape



Oct. 5, 1937.

S. HUGHES HEAT INSULATING TAPE Filed June 18, 1934 Patented ot.5,1937

HEAT INSULATING TAPE Samuel Hughes, North Charleston, S. C., assignor toRaybestos-Manhattan, Inc., Passaic, N. J., a corporation of New JerseyApplication June 18, 1934, Serial No. 731,066

10 Claims.

This invention relates toimprovements in thermal insulation and refersspecifically to a heat insulating tape or wrapping for pipes, conduitsand containers which carry fluids under relatively high temperatures,the tape being characterized in that it will not buckle when wrappedaround pipes or conduits of even relatively small diameters; theconstituent elements of the tape will not chafe or be placed under unduestress Iwhen wrapped; and that the confining sheath or envelope of thetape is continuous and seamless.

Heat insulating wrapping or tape has heretofore been used for wrappingpipes or conduits which carry fluids at relatively high temperatures.Such tapes usually comprise a core or body of heat insulating materialcovered by woven asbestos cloth, the cloth being folded longitudinallyabout the body material and the edges joined by stitching or adhesive.However, in view of the fact that cloth of this type is more or lessinexible, a stress is set up at the longitudinal seam of the coveringwhen the tape is wrapped about a pipe or conduit, which stress isintensified with pipes of relatively small diameters. More-over, thereis a tendency for the tape to buckle due to the inability ofl thecovering to conform to the curvature of the pipe. This results in aclumsy appearing wrapping and also renders it most difficult to properlywrap the pipe and eliminate leakage spacesbetween adjacent coils of thetape upon the fpipe.

Also, there is a tendency for the tape to distort across its width uponthe side in contact with the pipe, causing folds or buckles in and uponthe tape. Such buckling prevents full and complete contact between thetape and the pipe and provides pockets leading to joints of the tapethrough which heat will escape when the edges of adjacent coils are notin close contact. In addition, the ridges formed by said bucklingpresent high points of contact with the pipe which will tend to abradedue to the vibration of pipes not in rigid stationary position.

As a feature of my invention I confine a body portion of insulationwithin a jacket or envelope, braided or woven of asbestos yarn. 'I'hebraided jacket is not only without seams but possesses sufficientiiexibility to permit the tape to conform with the curvature of the pipewithout buckling. l As a further feature of my invention the bodyportion or filler of the tape comprises a relatively at, thin, flexiblesheet of asbestos paper, around which soft asbestos wicking or roving iswound in helical fashion, the roving completely covering the asbestossheet. This construction is such, that, when the wrapping is wound inspiral or helical fashion around a pipe, the clay between adjoininglayers or coils of the roving permits the tape to adjust itself upon thepipe without buckling. This feature permits the wrapping to be woundaround pipes of extremely small diameters.

Another feature of my invention resides in the provision of a core forthe tape or wrapping which comprises a relatively elongated, thin, fiat,fiexible sheet of asbestos paper, which, due to its shape causes thetape or wrapping as a whole to conform therewith, that is, remainrelatively flat, and, due to its composition, asbestos, serves as anadditional barrier to the conduction of heat.

lOther objects and advantages of my invention will be apparent from theaccompanying drawing and following detail description.

In the drawing, Fig. 1 is a side elevational View of a section of pipecovered by my insulating tape l or wrapping.

Fig. 2 is a fragmentary side elevational View of the insulating tape,parts being broken away to illustrate the component parts thereof.

Fig. 3 is a transverseA sectional view taken on the line 3-3 of Fig. 2.

Referring in detail to the drawing, I indicates a pipe or conduit whichmay be adapted to carry fluids at relatively elevated temperatures. Itis to be understood, of course, that although the tape or wrappingcomprising my invention is particularly adaptable for pipes or conduits,the Same may be utilized for containers, vats or the like in whichfluids under relatively high temperatures are maintained. The referencenumeral 2 indicates the tape or wrapping comprising my invention. Tape 2may comprise a relatively elongated, thin, flat, flexible core ofasbestos paper indicated at 3. wicking 4 may be wound or wrapped inhelical fashion around core 3, the adjacent coils 4 being disposed incontiguous relationship. The wrapping operation, when performed, is socarried out that vthe core 3 is maintained in its original shape. Inother words, the core 3 wrapped with the roving 4 is maintained intape-like form.

A sheath or envelope 5 of seamless construction may be either braided orWoven around the roving-covered core and forms a relatively flexiblecovering for the structure comprising the core and roving. The sheath orcovering 5 may be braided or woven of asbestos yarn or other heatresistant material.

It is to be understood, of course, that although my invention is shownand described as comprising an asbestos core, a bodyof asbestos rovingand a.covering comprising woven or braided asbestos yarn, otherinsulating materials may be used providing that they possess similarcharacteristics to asbestos with respect to flexibility and heatresistance. However, if the tape, 2` is utilized to insulate pipes,conduits, or containers which may carry relatively' cold fluids; suchas,refrigerator pipes, the material comprising the Relatively soft asbestosroving, rope or tape need only possess characteristics of heatinsulation and exibility.

In utilizing my invention tape 2 may be wound or wrapped in helicalfashion around pipe l, the

longitudinal edges of adjacent coils of the helix so formed-beingcontiguous, so as to provide a complete insulating covering for thepipe. By the provision of the paper core 3 the tape may be. convenientlywrapped in helical manner around the pipe without said tape losing itsshape or becoming distorted which would result in imperfect jointsbetween adjacent coils of the helical winding. Moreover, by theprovisiorrof the core 3 the tape 2 may be conveniently'handled andshipped. By the provision of the helically wrapped roving I, tape 2 mayybe wound or wrapped around a pipe or conduit of relatively smalldiameter, the play between adjacent coils of the helix 20 formed bytheroving preventing buckling of the tape even when said tape is wrappedaround pipes of diameters as small as V4 inch.

'I'he seamless sheath 5 is so woven or braided as to havecharacteristics of flexibility which permit a limited amount of play ofthe adjacent coils of the roving when said tape is wound aroundrelatively small pipes and conduits. In view of the fact that Athesheath 5 is constructed withoutseams,. no .parts thereof are undulyexposed to chafing. f

'Ihe tape 2 may be economically manufactured vin view of the fact thatthe roving 4 can be wound around core l by machine. In tapes of thischaracter heretofore produced with longi tudinal strands ofv roving, anumber of manual operations are necessary which increases cost.

' As a feature of the present invention the process of manufacturing thetape may be continuous. The paper core may take the form o f a ..740continuous strip Vunwound from aroll, being ted to that portion of themachine which wraps the roving in spiral, fashion around the core. 'I'hetension of the machine is adjustable to insure a tight winding aroundthe core as well as close 45 joints between'adiacent coils of the roundroving. The roving-covered core may be continufously fed to that-portionof the machine which braids or weaves the seamless sheath around theroving-covered core. 'Ihe tension of the weav- 50 ing or braidingl meansis adjustable to insure close contact between the sheath and therovingcovered core while at the same time permitting sufficient playtherebetween to adapt the tape to pipes of different diameters.

55 4 It is to be understood, of course, that although the drawingillustrates a winding composed of a number of strands, such winding mayconsist of la single strand, or several superimposed strands,

' depending upon the thickness desired in the final 50 product. Ifdesired, a single layer of roving may be provided by winding one or morestrands of roving l upon core 3 in the form of, for instance,

double or triple helices.

As an important commercial feature of my in- 35 vention, thetape 2 maybe manufactured and marketed in one width which maybe utilized upon .f awide range ofsizes of pipes or conduits. 'I'his results from the factthat the tape embodying the concept of my invention is so constructed 70that the filler or body` of the tape, namely the roving 4, may bereadilyl exed Awithout causing the tape as a whole to buckle when smalldiameter pipes are wrapped. Tapes utilized for analogous purposes aremanufactured'and marketed in varying widths depending upon thediameters` of the pipes or conduits to be wrapped. Obviously, thisresults in an economic loss which is obviated by my invention. 5

I claim as my invention:

1. An insulating tape adapted to be wrapped in helical fashion around apipe, conduit or container, comprising an elongated core of relativelyat asbestos paper, asbestos roving helically 10 wrapped around saidcore, and a fibrous sheath covering said core and roving.

2. An insulating tape adapted to be wrapped in helical fashion around apipe, conduit or container, comprising an elongated core of relatively15 flat asbestos paper, asbestos roving helically wrapped around saidcore, and a seamless fibrous sheath covering said core and roving.

3. An insulating tape adapted to be wrapped in helical fashion around apipe, conduit or con- 20 tainer, comprising an elongated core ofrelatively flat asbestos paper; asbestos roving helically wrapped aroundsaid core, the adjacent coils of roving comprising thehelix being incontiguous relationship with each other, and a'brous sheath 25 coveringsaid core and roving.

4. An insulating tape adapted to be wrapped in helical fashion around apipe, conduit or container, comprising an elongatedcore of relativelyflat lasbestos paper, asbestos roving helically 30 wrapped around saidcore, and a braided fibrous sheath covering said core and roving.

5. An insulating tape adapted to be wrapped in helical fashion around apipe, conduit or container, comprising an elongated core of relative- 35ly fiat asbestos paper, asbestos roving helically wrapped around saidcore, and a braided sheath.- of asbestos yarn covering said core androving.

6. lAn insulating tape adapted to be wrapped about a pipe, conduitorcontainer, comprising an elongated core of relatively thin, flatinsulating material, an insulated roving material wrapped about saidcore, and a flexible sheath covering about said core and roving.

7. A flexible insulating tape adapted to be wrapped about a pipefconduitor container, comprising an elongated core of relatively thin, flatinsulating material, and asbestos roving wrapped about said insulatedcore, and a seamless fibrous sheath enclosing said vcore and roving.

8. A flexible insulating tape adapted to b spirally wrapped about'apipe, conduit or container, comprising a cre of flat asbestos paper,asbestos roving wrapped about said paper! core in the form of aplurality of contiguous helices,

and a seamless, fibrous sheath enclosing said paper core and roving.

9. A flexible thermo insulating tape adapted to be wrapped about aypipe, conduit or container,

comprising an elongated core or fiat thin material that is relativelyflexible in longitudinal direction, an linsulated roving materialwrapped` said core and said roving.

- SAMUEL HUGHES.

